D guys! Suspension setting changes when going to 15" short rear tires
#16
Rennlist Member
Thread Starter
Thanks for the info I will lower a bit.
P.s. I did just break a minute, have Doc Bundy in a Lotus 23b, a Ginetta and another Lotus 23 ahead of me, too far ahead but will try to be fastest Porsche.
P.s. I did just break a minute, have Doc Bundy in a Lotus 23b, a Ginetta and another Lotus 23 ahead of me, too far ahead but will try to be fastest Porsche.
#17
Rennlist Member
Thread Starter
I lowered the pressures a bit to about 34 hot, and the rear was under control better, thanks!
Dick Strahota in his 911ST/2.8 started just ahead of me from a faster 1st session time and got a great start, I could not catch him and we both finished where we started after he had a great battle with two sports racers who finally got back by him.
It's still oversteering a bit and the bars are at extreme stiff (front) and loose (rear) settings so I guess I need a bigger front bar now.
Dick Strahota in his 911ST/2.8 started just ahead of me from a faster 1st session time and got a great start, I could not catch him and we both finished where we started after he had a great battle with two sports racers who finally got back by him.
It's still oversteering a bit and the bars are at extreme stiff (front) and loose (rear) settings so I guess I need a bigger front bar now.
Last edited by analogmike; 09-01-2012 at 09:19 PM.
#18
RL Technical Advisor
Before you do that, make absolutely certain that the rear suspension isn't bottoming out, even momentarily. That can do the very same things.
#19
Rennlist Member
If you are not bottoming out, just disconnect the rear bar. Many guys out on the West Coast dont even run a rear bar on these old cars. I broke my old sway bar mount, took it off at the track and went a second faster next session (Pre ST bodywork). However remember "Loose" is fast in these old cars.
#21
Rennlist Member
Thread Starter
Thanks for the info.
The car is not very low, and has the stiffest torsion bars made so I doubt it's bottoming. Every time a shop aligns the car it takes me a few races to make it handle right again... I wish I had time to do all the work on the car like I used to.
I have some soft Charlie Bars on the car which I got when I was running smaller torsion bars. I stiffened the front bar about 1/4" and I think it helped a bit but I worried that the lever arm was getting too short. I may try to tighten it a bit more tomorrow morning then get a bigger front bar. I need to try to get a good time in the morning so I don't want to make a large change like disconnecting the rear sway bar.
Here's how it looks, I think the ride height is about right, would like to lower the front a bit but the brake ducts are rubbing when I hit the uphill:
The car is not very low, and has the stiffest torsion bars made so I doubt it's bottoming. Every time a shop aligns the car it takes me a few races to make it handle right again... I wish I had time to do all the work on the car like I used to.
I have some soft Charlie Bars on the car which I got when I was running smaller torsion bars. I stiffened the front bar about 1/4" and I think it helped a bit but I worried that the lever arm was getting too short. I may try to tighten it a bit more tomorrow morning then get a bigger front bar. I need to try to get a good time in the morning so I don't want to make a large change like disconnecting the rear sway bar.
Here's how it looks, I think the ride height is about right, would like to lower the front a bit but the brake ducts are rubbing when I hit the uphill:
#22
Rennlist Member
Just disconnect the rear bar. You will immediately feel better. Trust me.
If you have over 31mm rear torsion bars.....That is what many people I know experienced when they went to 33mm....Too loose of a car.
31mm rear (TB) and 22mm front (TB) are the ticket on these old cars with Hoosiers.
If you have over 31mm rear torsion bars.....That is what many people I know experienced when they went to 33mm....Too loose of a car.
31mm rear (TB) and 22mm front (TB) are the ticket on these old cars with Hoosiers.
#23
Rennlist Member
Thread Starter
I have the biggest torsion bars available, 24 ft and 33 rear. It's still way too soft, but for vintage and PCA stock I can't run coilovers.
Removing the rear bar would save weight and solve the problem of ripping off the mounts. Will try it someday but not sure if I can take that chance in the morning unless I got a really fast race lap which would be used for my qualifying position for tomorrow's race.
thanks!!!!
Removing the rear bar would save weight and solve the problem of ripping off the mounts. Will try it someday but not sure if I can take that chance in the morning unless I got a really fast race lap which would be used for my qualifying position for tomorrow's race.
thanks!!!!
#25
Rennlist Member
You guys are crazy. Those are huge bars! I guess every car is different. Even PL said not to go any stiffer on my car.
I personally think you are over "bar'd". But what do I know about East coast tracks . Just have fun!
I have raced against Sarthota at RRIV. Nice guy. I would of beat him if I had some aero, and smarter lapped traffic
I personally think you are over "bar'd". But what do I know about East coast tracks . Just have fun!
I have raced against Sarthota at RRIV. Nice guy. I would of beat him if I had some aero, and smarter lapped traffic
#26
Rennlist Member
Yep - We are running 35 (or 36 in Sean's I think?)R and 24F but we did drop the rear sway diameters at the same time for better range. You can get a 36mm hollow rear but that's it and it was a special order at the time I bought mine. Not sure if the 73 TB's are the same spline as SC's but someone here will know.
#27
Rennlist Member
Thread Starter
Hi,
I found that it was the left rear swaybar mount bottoming out in the uphill, hard to believe as it's about 2" from the ground when level:
I lowered the right front 1/2 turn to try to fix the righthand oversteer/lefthand understeer problem and that helped a bit, plus the lower pressures. But the car is not much faster with the improved gearing and wider/lower rear tires. Maybe because my stock 2.7 RS engine is not very strong up top. Need data but my logger was not working.
A Lotus bit off one of my supertrapps in the final race, making my car run quite poorly, but a Ginetta had slightly worse problems, right in front of me, luckily he landed like a cat and walked away...
I will need a bigger front bar (or can try to disconnect the rear but I love using it for quick adjustments) and maybe more rear camber to make these work, I think there is 2.5 in the rear and I prefer 2.75.
Thanks for the advice, I had a lot of fun at the race.
I found that it was the left rear swaybar mount bottoming out in the uphill, hard to believe as it's about 2" from the ground when level:
I lowered the right front 1/2 turn to try to fix the righthand oversteer/lefthand understeer problem and that helped a bit, plus the lower pressures. But the car is not much faster with the improved gearing and wider/lower rear tires. Maybe because my stock 2.7 RS engine is not very strong up top. Need data but my logger was not working.
A Lotus bit off one of my supertrapps in the final race, making my car run quite poorly, but a Ginetta had slightly worse problems, right in front of me, luckily he landed like a cat and walked away...
I will need a bigger front bar (or can try to disconnect the rear but I love using it for quick adjustments) and maybe more rear camber to make these work, I think there is 2.5 in the rear and I prefer 2.75.
Thanks for the advice, I had a lot of fun at the race.
Last edited by analogmike; 09-04-2012 at 11:01 PM.
#30
Rennlist Member
Thread Starter
It's not curbing, I think it's in the uphill when I hit the hill and the suspension compresses. It's a 1G+ corner plus a VERY steep, abrupt hill, so the left side gets really low...